A projective capacitive touch screen is formed by adding two groups of transparent conductive lines (along X and Y axes respectively) into a conventional capacitive touch screen, the two groups of transparent conductive lines are located in different planes respectively and perpendicular to each other. When, for example, a finger touches the touch screen, a change of capacitance at a touch position of the finger can be detected by scanning along X and Y axes, thereby the touch position of the finger is calculated.
A conventional projective capacitive touch screen comprises an array substrate and a color filter substrate which are aligned and combined with each other, liquid crystal and a main photo spacer are provided between the array substrate and the color filter substrate, wherein, for example, an emitting electrode and a receiving electrode are provided on a surface of the color filter substrate away from the array substrate, a capacitance is formed between the emitting electrode and the receiving electrode, the emitting electrode emits an excitation signal to the receiving electrode, the receiving electrode transmits the excitation signal to a processor. When a finger touches the surface of the touch screen, the capacitance between the emitting electrode and the receiving electrode changes, resulting in a change of characteristic of the excitation signal received by the receiving electrode, the changed excitation signal processed by the processor can be used for identifying a touch action of the finger.
However, the projective capacitive touch screen described above can only identify the touch action of the finger, but cannot identify different touch pressures of the finger, that is, cannot perceive whether the finger presses the touch screen lightly or heavily.